It is often desirable to identify and delineate segments or objects in an image. Information regarding segments or objects in an image may be used to facilitate digital image or video processing.
In certain circumstances, a previously hidden area of an image may become uncovered. For example, in video processing, a frame may include various segments or objects. In a subsequent frame, one or more of the segments or objects may move. Where a segment or object used to be (prior to moving), a previously hidden area may become visible.
Processing such newly uncovered areas can be problematic and done inefficiently. For example, when similar areas become newly uncovered in MPEG encoding (due to movement of blocks), MPEG applies discrete cosine transform (DCT) coding to the newly uncovered areas and transmits the entire newly uncovered image region to the decoding device. This approach is disadvantageous in that it results in inefficient image compression.